The present invention relates generally to a high-power pulsing circuit and more particularly to a repetitive-pulse inductive energy storage and transfer circuit.
Many applications requiring power in the form of a train of high-power pulses are emerging from major programs within the Department of Energy and Department of Defense communities. Included among these applications are high-repetition-rate particle accelerators and lasers, pulsed microwave generators, high-power high-resolution radar, and induction heating systems. When the pulse-train duty factor (pulse width/pulse interval) is low, energy storage capability is needed to provide proper power conditioning. Inductive energy storage is attractive for these systems because it has both a high energy storage density and a fast discharge capability. However, to transfer energy from a coil or inductor to a load, an opening switch must be used to interrupt the current and insert the load into the circuit. The opening switch must carry the large coil current during the storage time, interrupt the current, and then withstand the high voltage generated by the coil current flowing through the load. The opening switch problem is difficult enough for single-shot operation, but it becomes almost impossible when repetitive operation is required.
Two types of repetitive-pulse operation of inductive storage systems have appeared in the literature. The first uses a rotary, mechanical opening switch to generate pulses at moderate power levels and repetition rates (about 1 MW and 60 pulses per second (pps), respectively) with a low impedance load, see D. Bauer and J. Barber, "A Repetitive Current Interrupter for an Inductive Energy Storage Circuit," Proc. 4th IEEE Pulsed Power Conf., Albuquerque, N.M., June 6-8, 1983, IEEE Pub. No. 83CH1908-3, pp. 98-101. Due to its mechanical construction and nature of operation (sliding brushes), the rotary switch has essentially no potential for meeting the high-power, high-repetition-rate pulse requirements of the DOE and DoD applications discussed earlier.
The second uses an explosive opening switch and a string of fuses to produce a train of 3-5 pulses at a peak power level of 2.6 GW and a pulse repetition rate of about 50 kpps, see R. D. Ford and I. M. Vitkovitsky, "Inductive Storage Pulse-Train Generator," Proc. 13th Pulse Power Modulator Symp., Buffalo N.Y., June 20-22, 1978, IEEE Pub. No. 78CH1371-4-ED, pp. 284-288. The need to replace the explosive opening switch and fuses between each burst of pulses severely restricts the use of this method, limiting it primarily to the research laboratory.
Therefore, it is an object of the present invention to provide a high-power repetitive-pulse inductive energy storage and transfer circuit.
It is another object of the present invention to provide an efficient high-power inductive energy transfer circuit having a reusable opening switch.
It is another object of the present invention to provide a repetitive-pulse inductive energy storage and transfer circuit having complete control (pulse-to-pulse) over output pulse initiation and repetition rate, pulse duration, and, to some extent, pulse risetime.
It is still another object of the present invention to provide a reversing-counterpulse repetitive-pulse inductive storage and transfer circuit which can provide a repetitive counterpulse to the main opening switch without using a bridge arrangement for the counterpulse capacitor.